It is becoming apparent that in the future new battery systems, on which very high demands are made in terms of reliability, safety, performance and service life, will be used in stationary applications such as wind-power plants, in motor vehicles which are embodied as hybrid motor vehicles or electric motor vehicles and in electronic equipment such as laptops or mobile phones.
Lithium-ion batteries will play a key role in the electrification of the drive system. As in most other electrical energy accumulators, in lithium-ion batteries the performance and durability are also dependent on the temperature. At low temperatures, the charging capability and the extraction of energy are limited, while at high temperatures the energy accumulator ages more quickly. Even with future battery technologies there is expected to be a certain dependence upon the temperature.
Such lithium-ion cells usually comprise an electrode which can reversibly embed lithium ions in the course of what is referred to as intercalation or can export them again in the course of what is referred to as deintercalation. Intercalation takes place during the charging process of the battery cell, and the deintercalation takes place during the discharging of the battery cell in order to supply current to electric assemblies.
Owing to the relatively high energy density, lithium-ion batteries are used in a variety of ways. Lithium-ion technology is predestined for a wide field of application. It is characterized, inter alia, by high energy density and extremely low self-discharging.
High driving power levels of electric vehicle drives require high electrical voltages or currents from the accumulator and electric machines. The safety of the vehicle occupants and, in particular, of emergency services has to be ensured in all situations, for example even in the event of a fault due to damage to the cables or to a reduction in the distances from voltage-conducting parts.
The service device which is used according to the prior art and regulations is in itself not sufficient to ensure the safety of the vehicle occupants. The service device is provided for maintenance purposes and is mounted in a concealed manner on the vehicle with the result that the service device usually can only be actuated after the vehicle is touched.
The service device itself is often very difficult to access since it is mounted on the battery housing itself. The battery housing is mounted with a low center of gravity (for example the underfloor of the vehicle) owing to the driving dynamics and driving stability (for example the tendency to tilt during the calibration test).
DE 10 2009 057 007 B4 discloses a vehicle, in particular a hybrid vehicle and/or an electric vehicle, having a controllable main switch for a voltage supply and a fuse which protects the main switch against unauthorized operator control. The operator control is carried out outside the vehicle. Furthermore, the vehicle has a fuse disconnecting means which disconnects and/or switches off the fuse and therefore authorizes operator control of the main switch if an accident and/or service failure are/is detected.